Endoprosthesis for a hip joint socket

Abstract

The hip joint endoprosthesis has a plastic socket body with a hemispherical outer surface and a wire mesh metal grid partially embedded in the socket body surface. The metal grid has a plurality of rib-like projections extending outwardly along meridian lines of the socket body in order to define regions therebetween for receiving a minimum thickness of bone cement for anchoring of the endoprosthesis in a bone.

What is claimed is: 
     
       1. An endoprosthesis for a hip joint socket comprising an inner plastic socket body having a hemispherical outer surface; and   a multi-layer metal grid fixed to said surface of said body, said grid forming a plurality of uniformly distributed rib-like projections extending outwardly along meridian lines for contacting bone while defining regions therebetween to receive bone cement, said projections being disposed on opposite sides of a rib-free region medially of said surface and in offset relation to each other.   
     
     
       2. An endoprosthesis as set forth in claim 1 wherein said grid is countersunk in a polar region relative to said projections. 
     
     
       3. An endoprosthesis as set forth in claim 2 wherein said grid is partially embedded in said body to at least partially fill said projections. 
     
     
       4. An endoprosthesis as set forth in claim 1 wherein said grid is partially embedded in said body to at least partially fill said projections. 
     
     
       5. An endoprosthesis for a hip joint socket comprising a plastic socket body having a hemispherical outer surface; and   a wire mesh metal grid partially embedded in said surface of said plastic body, said grid forming a plurality of rib-like projections extending outwardly thereof for contacting bone while defining regions therebetween to receive a bone cement bed said projections being disposed along meridian lines of said hemispherical surface.   
     
     
       6. An endoprosthesis as set forth in claim 5 wherein said projections are disposed in two circumferential rows with a projection-free zone therebetween. 
     
     
       7. An endoprosthesis as set forth in claim 5 wherein said projections extend to a polar region of said grid whereby said polar region is countersunk relative to said projections. 
     
     
       8. An endoprosthesis as set forth in claim 5 wherein said projections are uniformly distributed over said socket surface. 
     
     
       9. An endoprosthesis as set forth in claim 5 wherein said grid is of multi-layer construction.